1. Related Applications
This application claims priority to Russian Application No. 99103911 filed Mar. 1, 1999 and PCT/RU00/00045 filed Feb. 9, 2000.
2. Field of the Invention
The invention is pertaining to technology of electronic devices that can be used as multifunctional electronic cards.
3. Description of the Related Art
There are electronic cards comprising functional elements placed between two plates. In particular, those cards include a microelectronic element which provides data storage and processing, a power supply element, a liquid crystal (LC) display, and a system for connecting with internal and external elements (EP 0498582, 1992; GB 2275654, 1994). Those elements are protected with two plates.
Several drawbacks are inherent in known electronic cards. In particular, some functional elements of the electronic card such as the microelectronic element and display are separate devices which are built during assembly of the card between the two plates. Such design requires use of a special connection between electronic elements and other elements of the card ensuring reliable electrical contact between them. Presence of several devices between two thin plates reduces mechanical durability of the design as a whole. Besides, the techniques of manufacturing liquid crystal displays used in the cards prevent manufacturing of elements of the card and display within a single technological process.
The technical results of the invention proposed herein are simplification of the electronic card design, opportunity to devise a single process of manufacturing of the card together with the display, reduction of the card thickness, increase of mechanical durability, productivity and feasibility of card manufacturing, as well as increase of reliability of the card.
The claimed technical result is achieved because, in a smart card (electronic card) containing two plates with the functional elements placed between and/or on them, the design of the card including a display with a liquid crystal display element, and possibly containing a microelectronic element, a power supply element, a keyboard, a system for communication with internal and external elements and/or other elements, the liquid crystal display element is the element containing two walls comprising appropriate electrodes or systems of electrodes formed on the internal surface sides of the walls; with at least one layer of polarizer and liquid crystal placed on top of the said electrodes or system of electrodes, while at least one of the said plates of the card serves as one of the walls of the display element, and the appropriate electrode or system of electrodes is formed on the internal surface of the said plate.
The second plate of the card may be used as the second wall of the display element, with appropriate electrode or system of electrodes formed on the internal surface side of the card.
A reflective-type element may be used as the display element, with the electrode or system of electrodes of at least one of the walls in the reflective-type display element made of optically transparent material, and a diffusely reflecting layer placed on the surface of the other wall. Then, the diffusely reflecting layer may also form the electrode or system of electrodes of the said other wall.
One of the walls of the element in the reflective-type display element may be made of optically transparent material, while the second wall, on which is a diffusely reflecting layer is designed, may be made of single-crystal silicon, or metal, or glass, or plastic.
A birefringent layer may be placed between the diffusely reflecting layer and the liquid crystal or between the liquid crystal and the polarizer layer in the reflective-type display element.
The system of electrodes may be made of electrically conductive polymer for at least one of the walls of the display element.
At least one of the polarizers may be implemented as a molecularly oriented layer of dichroic dye capable to forming a lyotropic liquid crystalline phase.
To display the output data in color, a layer of color matrix or pattern is formed on the internal-surface side of one of the walls of the display element between the wall and one of the polarizers.
At least one of the polarizers may be manufactured from polarizing elements differing in color and/or in the polarization axis direction.
At least one of the polarizers may be placed on an optically transparent electrode, or between the wall and the electrode, or on the insulating sublayer covering the optically transparent electrode, or between the alignment layer located on the polarizer and the electrode, or between the alignment layer and the insulating sublayer covering the electrode
Due to the claimed set of attributes, the display used in the card can have the optical path not exceeding 10 microns.
At least one auxiliary plate with windows to position the appropriate functional elements may be placed between the external plates of the card, this auxiliary plate being a delimiter.
The liquid crystal display may be implemented such as to include a touch screen and a digital and/or alphanumeric tablet for data input.
The technical result of the method of manufacturing the electronic card consists in the opportunity to provide a single process of card manufacturing combined with display manufacturing, increase of productivity and feasibility.
The specified technical result of the claimed method is achieved because, in the method of manufacturing a smart card (electronic card) providing positioning of functional elements on at least one of the two plates of the smart card and joining the plates, a display based on a liquid-crystal display element with an internal polarizer is used as one of the functional elements of the card, the display element being formed during card manufacturing, with at least one of the plates of the card used as one of walls of the display element, and the appropriate electrode or system of electrodes of the display element formed on the internal-surface side of the latter plate of the card.
The second plate of the card may be used as the second wall of the display element, with the appropriate electrode or system of electrodes of the display element formed on the internal-surface side of the second plate of the card.
For the reflective-type display element, the electrode or system of electrodes of at least one of the walls is made of optically transparent material, on top of which a polarizer layer is formed, and a diffusely-reflecting layer is formed on the surface of the other wall, with at least the part of the card plate which is the wall of the display element made of optically transparent material.
The diffusely reflecting layer may form the electrode or system of electrodes of the said wall.
A birefringent layer is formed on the surface of the diffusely reflecting layer from one side, or on the surface of the polarizer layer from the other side.
At least one polarizer layer is formed on an optically transparent electrode, or on the wall of the display element, or on the insulating sublayer covering the optically transparent electrode.
The procedure of forming the system of conductors ensuring switching of the functional elements on at least one of the card plates is performed before or after formation of the electrode or system of electrodes of the display on that plate, or simultaneously, in a single work cycle. The electrodes and conductors can be made of the same material, or of different materials.
When the functional elements are deposited, at least one intermediate plate is imposed on at least one of the card plates, the intermediate plate having windows to place the appropriate functional elements, and the functional elements are placed on the plate before imposing the intermediate plate, or after, in the appropriate windows, or partially before and partially after.
The liquid crystal layer of the display element is formed on the polarizer surface of one of the card plates before joining the card plates, or after joining the card plates, by flood-filling.
A transmissive-type element can be used as the display element, with system of electrodes of both walls of that element made of optically transparent material.